BRC-BIO: Determining the neural mechanisms regulating photostimulation of migratory physiology and behavior

BRC-BIO：确定调节迁移生理和行为的光刺激的神经机制

• 批准号: 2233190
• 负责人: Jonathan Perez
• 金额: $ 47.89万
• 依托单位: University of South Alabama
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2024
• 资助国家: 美国
• 起止时间: 2024-01-01 至 2026-12-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2233190&HistoricalAwards=false
• 关键词: BRC; BIO; Determining; neural; mechanisms

This project will allow us to understand how the brains of songbirds use environmental information to time seasonal migrations. Unlike resident species, migratory birds are particularly susceptible to environmental change as they must move through multiple environments each year. They must time migratory journeys without direct knowledge of environmental conditions at their destination, relying on generalized seasonal cues, specifically the seasonal change in day length, photoperiod, to appropriately time departure. However, we still know very little about the pathways in the brain that process photoperiod information into the complex changes in physiology and behavior necessary to support migration. In particular, the shared reliance of both migration and preparation for reproduction on the same seasonal photoperiod cues has limited our ability to understand how migratory timing is controlled. This project will use previously identified lighting regimes to isolate migratory physiology from reproduction in order to identify those neural mechanisms specific to migration. By understanding how animals use photoperiod cues to time migration we will be better able to predict the scope of environmental change to which migratory birds can flexibly respond, informing conservation efforts. This project will create funded research opportunities for multiple undergraduate students to broaden the population of students able to participate in undergraduate research by alleviating the choice between research and a paying job. Building on the equipment and resources developed by this project, a series of public outreach resources on migratory bird physiology and behavior will be developed for use at events both locally and throughout the Alabama Gulf Coast community. The project was jointly funded by the BRC BIO program and the Established Program to Stimulate Competitive Research (EPSCoR).This project addresses the fundamental questions of how songbirds detect and integrate photic cues from their environment into the complex array of changes in physiology, morphology, and behavior necessary to support spring migration. Photoperiod changes are well established as a predictive cue controlling migratory timing for many species. However, the mechanisms underlying timing of migration remain obscured. This is because both seasonal migration and reproduction both rely on increasing spring photoperiod as a cue and require thyroid hormone signaling within the brain to occur. This overlap between migratory and reproductive mechanisms has limited the utility of observational studies that aim to identify neural mechanisms, as well as the efficacy of simple manipulative efforts such as thyroid knockouts. This project leverages a previously established low intensity green light paradigm to photostimulate the development of vernal migration without triggering reproductive physiology in the well-studied white-crowned sparrow system. The project will then localize neural expression of deep brain photoreceptors capable of detecting this low intensity green light cue by developing custom antibodies for immunohistochemistry. Then through multi-target in situ hybridization analysis, it will identify migration specific changes in neural thyroid hormones signaling. Finally, the direct role of putative photoreceptor candidates in regulating migratory physiology will be tested by AAV2 viral vector-mediated shRNAi knockdown of opsin expression in the brain followed by stimulation of migration using the green light paradigm. This work will provide novel insight into the neural mechanisms and the potential plasticity of migratory timing.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

这个项目将使我们了解鸣禽的大脑如何利用环境信息来确定季节性迁徙的时间。与留鸟不同，候鸟特别容易受到环境变化的影响，因为它们每年必须穿越多种环境。他们必须在不直接了解目的地环境条件的情况下，依靠一般的季节线索，特别是白天长度、光周期的季节变化，来确定迁徙旅程的时间，以便适当地确定出发时间。然而，我们仍然对大脑中将光周期信息处理成支持迁移所需的生理和行为复杂变化的途径知之甚少。特别是，共同依赖的迁移和准备繁殖相同的季节性光周期线索限制了我们的能力，了解迁移时间是如何控制的。该项目将使用以前确定的照明制度，以隔离迁移生理生殖，以确定特定的迁移神经机制。通过了解动物如何利用光周期线索来确定迁徙时间，我们将能够更好地预测候鸟可以灵活应对的环境变化范围，为保护工作提供信息。该项目将为多名本科生创造资助的研究机会，通过减轻研究和有偿工作之间的选择，扩大能够参与本科研究的学生人数。在该项目开发的设备和资源的基础上，将开发一系列关于候鸟生理学和行为的公共宣传资源，供当地和整个亚拉巴马墨西哥湾沿岸社区的活动使用。该项目由BRC BIO计划和刺激竞争研究既定计划（EPSCoR）联合资助。该项目解决了鸣禽如何检测环境中的光线索并将其整合到支持春季迁徙所需的生理、形态和行为的复杂变化中的基本问题。光周期的变化是一个很好的建立作为一个预测线索，控制许多物种的迁徙时间。然而，迁移时间的基本机制仍然模糊不清。这是因为季节性迁移和繁殖都依赖于增加春季光周期作为线索，并需要大脑中的甲状腺激素信号发生。迁移和生殖机制之间的这种重叠限制了旨在确定神经机制的观察性研究的效用，以及甲状腺敲除等简单操作努力的功效。该项目利用先前建立的低强度绿色光范例，在充分研究的白冠麻雀系统中，光刺激春季迁移的发展，而不触发生殖生理学。然后，该项目将通过开发用于免疫组织化学的定制抗体来定位能够检测这种低强度绿色光提示的脑深部光感受器的神经表达。然后通过多靶点原位杂交分析，确定神经甲状腺激素信号转导的迁移特异性变化。最后，将通过AAV 2病毒载体介导的视蛋白表达的shRNAi敲低，随后使用绿色光范例刺激迁移来测试推定的光感受器候选物在调节迁移生理学中的直接作用。这项工作将为神经机制和迁移时间的潜在可塑性提供新的见解。该奖项反映了NSF的法定使命，并且通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。